Arc-lamp electrode.



UNITED STATES PATENT. oEFIoE.

wrnum n. MOTT, or nannwoon, OHIO,.ASSIGN'QB, BY mns'nn ASSIGNMENTS, 'ro

. narrower. cannon commnr, me, A conronuron or new YORK.

ARC-LAMP nnnbrnonn.

No Drawing.

The ,highest candle power in commefcral' are lights has hitherto been obtained by the use of calcium fluorid as the main con stituent, which produces a yellow flame. Yellow flame arcs are well adapted for lighting smoky or foggy places, on account of. the great penetrating power of the yellow rays.

Incertain cases, however, a pure white light is adesideratum, this being particularly true of photographic and photo engraving work. For general street lighting also, a white light is to be preferred.

In making flame electrodes for photographic andphoto engraving work it has con customary to use rare-earth fiuorids' alone or in combination with other salts instead of using calcium fluorid. Calcium fluorid is considered to be the best all around flaming constituent that can be used in are lamp electrodes, but the yellow character of its light has heretofore hindered itsilse in photographic lamps. My invention enables me to use calcium fluorid and thusobtain the high candle power incident thereto, while producing a snow white light.

Uranium in the electric are probably gives more lines in the spectrum than any other known element, and the arc is exceptionally rich in the blue and violet rays, while it also contains a considerable number of ultraviolet rays. Uranium therefore has a unique distinction of giving 50% more photographic power when used in, the'arc than rare-earth fluoride, or titanium oxid, which have heretofore been considered the materials having f the" highest photographic values.

Uranium has agreat propensity to form various, chemical reactions with other substances when incorporated in thearc, and inasmuchas the candle power 0 the are increases-with the number of chemical com- Specification of Letters Il'atent.

cium fiuorid in making up an 'rays of the latter to produce ail; It snow white light of extraordinary uranium, the

Patented Aug. 7, 1917.

Application filed September 25, 1814. Serial No. 883,463.

is a desirable material to be used in elee-' trodes for this if for no other reason Uranium materials producean sari having an intense blue center rich properties, and when it is mixed electrode it fully blends with t graphic powen- There are various uranium chmpoundb that may be used to combine with calcium fluorid, such as the various oxids of uranium, uranates of calcium, strontium and other metals, metallic uranium, uranium carbid, uranium nit-rid, uranium borate, uranium tluorid, uranium oxyfiuorid and others.

Of the various compounds available I have found that the oxide of uranium and the uranates of calcium and strontium are the most eflicient' for the purpose mentioned.

Uranium oxid or fiuorid, when used alone in the are, gives 50% more photographic power than any other material with which I am familiar.

Strontium .uranate gives an red shell and an intense blue core so that are with a so I the composite eflect is ,a white light having 15 to 20% more photographic power. than the rare-earth fluorids for instance. although most strontium compounds give hardlyhalf the photographic power of such fluoride, This salt therefore, when used alone or in flamers.

The use of uranium salts and materials is.

not restricted to any definite amounts in proportion to the other materials in the,

electrode, but merely by way of example it may be stated that in cored electrodes for.

instance, the paste may consist of about 40% core black and 60% flaming material, which 1 may consist entirely of uranium salts, oxids or other uramummaterial. When calcium fluorid is to be used In comunction with to blend with e uranium raysto produce. a.

snow white light.

Having described my invention, what I claim is r p 1. An arc lamp electrode containing an proper amount. will be used oxywompound of uranium and acddm/itinI m flllm'i'd an oxid ofi lii'.anilun and a conbody of carbon. I? I v 2. An arc lamp electrode containing al- In testimony. 'w'vi eil eofl I hereunto aflix "cium flliorid and a uranium material. I niy signature. 1 1-;

6 3. An arc lamp electrode containing 0511- :WILLIAM R. MOTT.

cium-fluorid uranium material and a, con- Witi1essesav ducting body. PHILIP I. BETHEA,

4. An arc lamp electrode containing 0311- "H.-

GRovER.

ducting; body. 10' 

